This protocol is a pilot study that will investigate the use of riluzole in patients with Huntington's Disease (HD). Riluzole has shown promise in the treatment of amyotrophic lateral sclerosis, another neuro- degernative disorder. The investigators will administer riluzole to 8 subjects with HD for 6 weeks as an open-label study. The study endpoint will include changes in brain lactate levels as measured by MR spectroscopy following administration of the study drug and four weeks after stopping medication.